Art of tanning hides and skins



Aug; 28, 1934. M. M. MERRITT n ART 0F TANNING HIDES ND' SKINS Filed Jan. 24, 1931 2 Sheets-Sheet l Aug'. 28, 1934. M. M.y MERRLTT ART OF TANNING HIDES AND SKINS Filed Jan; 24, 1931 2 Sheets-Sheet 2 Patented Aug. 28, 1934 l ART OF TANNING HIDES AND SKINS Matthew M. Merritt, Middleton, Mass., assigner to The Tanning Process Company, Boston, Mass., a corporation of Massachusetts Application January 24,1931, Serial No. 511,026

17 Claims. (CL`149--4) with 'both the preparation of the hides and skins and the tanning thereof, and to reduce greatly the handling of the hides and skins. Other objects of the invention are to speed up production and at the same time reduce the labor cost incidental to tanning operations.

To these ends and in accordance with an im- 20 portant characteristic of the invention a hide or skin is nrst slicked out upon a portable backing of such a nature that it will maintain the hide or skin fully extended While it is being treated. It is especially advantageous in tanning operations to have the hide or skin slicked out in fully extended condition upon a portable backing since the slicking out operation causes the hide or skin to adhere to the portable backing to maintain the full normal area of the hide or skin While it is undergoing treatment by a tanning material, a treatment which very frequently resulted in shrinkage. of the hide or skin when carried out in accordance with methods commonly in use in the past. While the tanning material isacting on the hide or skin maintained in fully extended condition by its backing, the hide or skin and its backing may be transferred as a unit to some other location or it may be stacked with other similarly treated units.

40 From another viewpoint the invention comprises spreading a. hide or skin out upon a backing having exible marginal portions, bending the marginal portions upwardly to convert the backing into a liquid container, and applying a treating liquid to the hide or skin while the latter is maintained by its backing in its extended condition. In practising the method referred to in the foregoing sentence, a hide or skin .is first spread out Ain extended condition upon a portable backing after which a treating liquid is applied to the exposed surface of the hide or skin While the latter is maintained in its extended condition by its backing. Subsequently the hide or skin is reversed upon its backing to expose the other surface, after which the flexible marginal portions of the backing are bent upwardly to convert Vthe backing into a container for liquid, and then more of the treating liquid is applied to the exposed surface of the hide or skin while-the latter is still maintained in extended condition on its backing.

From still another viewpoint the invention comprises subjecting a hide or skin while spread out upon a portable backing to treatment. by a treating uid and subsequently stacking the port- 65 able backing with its treated hide or skin with other similar backings having similarly treated hides or skins thereon. Not only is considerable space saved in the factory by thus stacking the hides or skins and their portable backings but the treating liquid may continue to act While the hides or skins and their backings are thus stacked.

It is practical, for instance, to apply a tanning material to light skins While they are upon their portable backings and to comp.1 ete the tanning while they and their backings are maintained in stacked relation. In the case of heavier hides or skins, each hide or'skin may be removed from its backing after it has set in extended condition due to partial tanning by the tanning material, and then be subjected to further tanning operations either in a Vat or in a drum. Alternatively, the hides or skins and their backings may be restacked, during which operation fresh tanning material is added to the exposed surface of each hide or skin while the latter remains in extended condition on its backing.

It is to be understood that the method of tanning hides and skins herein disclosed is, in its broader aspects, disclosed and claimed in my J0 copending application, Serial No. 402,319, iiled October 24, 1929.

For use in practicing the method described and claimed herein, there is provided a plurality of Work supports or backing members each comprising a sheet of flexible material of a size suitable for the Work to be handled and having marginal portions readily bendable above the level of the body portion thereof whereby each sheet may serve not only as a support for a hide or skin but as a container which will hold the desiredamount of treating liquid applied to the hide or skin thereon. When stacked, or when placed individually on a proper support or table, for instance a table having raised marginal portions, the marginal portions of each work support are bent upwardly by said raised marginal portions so as to hold a certain amount of treating liquid in contact with the upper surface of the sheet and of the piece of work thereon. The lightness of the work support, consisting as it does of a sheet of material without edge pieces or thickened portions, contributes to the facility with which it is moved about. I have found that sheets of linoleum, of rubber or rubberized fabric, and of Quaker felt possess all of the described advantages as backing members or work .supports because of their lightness, and the readiness with which they may be caused to hold treating liquid as a container.

These and other important characteristics of the invention will now be described in detail and then pointed out more particularly in the appended claims.

In the drawings,

Fig. 1 is a view in side elevation of an apparatus for use in the treating of hides and skins;

Fig. 2 is a plan view from above of Fig. 1, (on the line II--II of Fig. 1) with parts omitted, in order to show to better advantage the sequence of operations upon the work;

Fig. 2a. indicates a vat used in connection with the machine illustrated in Figs. 1- and 2;

Fig. 3 is a detail sectional view of a support for the work;

Fig. 4 is a view similar to Fig. 1 illustrating a modification in the method of treating hides and skins;

Fig. 5 is a plan view from above, taken along the line V-V of Fig. 4; and

Fig. 6 is a. sectional View taken along the line VI-VI of Figs. 1 and 4.

The illustrated apparatus, which was designed specially for the practice of the novel method of tanning herein described and claimed, forms the subject-matter of an application, Serial No. 643,577, filed Nov. 2l, 1932 as a division of this application.

As shown, the apparatus embodies a conveyor mechanism 10 (Figs. 1 and 2) comprising an endless belt conveyor 12 arranged to pass around two end rolls 14 and 16, the latter being driven through a sprocket wheel 18 which is fixed to shaft 20 of the roll 16. Passing around the sprocket wheel 18 is a chain 22 also passing around a second sprocket wheel 24 on a shaft 26 carrying a sprocket wheel 28. Passing around the sprocket wheel 28 is a chain 3i) which also passes around a sprocket wheel 32 on the shaft of a motor 34 which serves as a convenient source of power for moving the belt conveyor 12. The upper runk of the belt conveyor 12 rests upon a smooth, fiat table B6.

Since the belt conveyor 12 is relatively wide and heavy and made of rubber, or of rubberized fabric,

-means is provided for lubricating the under side of the belt conveyor 12 and the upper surface of the table 36 to lessen friction and thereby facilitate theoperation of ,the motor employed in moving the belt conveyor over the table. Conveniently water is used as the lubricating liquid. For wetting the belt conveyor 12 and for discharging water upon the upper surface of the table 36, between such surface and the under side of the belt conveyor 12, here is provided in the illustrated construction a main pipe 40 from which there extends a number of branches, one of which is shown at 42 in Fig. 1 of the drawings. This branch pipe 42 has an upwardly extending end piece 44, the mouth of which opens upon the upper surface of the table 36 below the upper run of the belt conveyor 12. Several of these branch pipes` 42 are employed in the length of the table to insure proper lubrication between the table 36 and belt conveyor 12 when the table and belt are relatively long as shown in Fig. 4` each branch pipe 42 being provided with a valve 46 controllable by a hand wheel 48 so that the amount of water discharged may be regulated in accordance with the judgment of the operator. As shown most clearly in Fig. 6 the branch pipes 42 discharge upon the upper surface of the table 36 at points located substantially upon the longitudinal center .line of the table.

For collecting and discharging the excess lubricating liquid there is provided at each edge of the table a trough 50 (Figs. 1 and 6) each trough being provided with a discharge pipe such as that shown at 52 (Fig. 6) which leads to a larger` discharge pipe 53 (Figs. 1 and 4). Preferably and as shown the discharge pipe 53, at its lower end is located above a large trough 56 which discharges into any convenient sewer through a pipe 58 (Fig. 4).

While the hides or skins are resting upon the upper surface of the belt conveyor 12 certain operations may be performed, such as that of slicking out each hide or skin whereby a considerable proportion of the watery content of each hide or skin is removed therefrom, and then applying tanning material to the slicked-out hide or skin. Means is provided for draining Waste watery material, produced by the slicking-out operation, from the upper surface of the traveling belt conveyor, this means conveniently comprising, in the illustrated machine, the troughs 50 which, as stated, are utilized in the discharge of the excess lubricating liquid. By having the trough under the longitudinal edges of the belt conveyor 12, the latter overhangs at its edges the said troughs 50 and readily discharges into the troughs the waste material from the rides and skins. Hence the troughs 50 and the connected pipes 52 discharge not only excess lubricaitng liquid but the waste material from the hides and skins.

As most clearly shown in Figs. 1 and 4 of the drawings the lower run of the belt conveyor is relatively slack and is carried by a plurality of rollers 60. Between two adjacent rollers 60 there is located a small tank 62 containing water, the arrangement being such that the lower run of the belt conveyor dips down into this tank of water and is washed on both of its surfaces as it passes lengthwise of the tank. The tank 62 is conveniently supplied with water by means of a branch pipe 64 extending from the main pipe 40 of the water lubricating system, a valve 66 be ing provided in the pipe 64 for controllinglthe supply of water to the tank 62. The main pipe 40 of the water lubricaing system may be attached to the water supply pipe of the factory in which the machine is located.

At the entering end of the belt conveyor 12 there is provided a feeding-in table '70 (Fig. l) up which pieces of work may be shoved for engagement with the belt conveyor 12. While on this table, tanning material may be applied to the work by a worker standing on a platform 73, Conveniently, and as shown, each piece of work, whether a hide or skin, is placed upon a portable backing or work support '71, a stack of such backing-members or work supports being shown at '72 resting upon the supporting surface of a table truck 74. At the discharge end of the belt conveyor l2 there is provided a discharging table 75 consisting of a number of slats having beveled end portions located closely adjacent to the belt conveyor 12 where it starts downwardly around the roll 16 so as to take each portable backing member or work support 71 from the conveyor as it reaches this poi/nt in its travel. A- workman will remove each backing member or work support with the'work thereon from the discharge table 75 and place it upon the supporting surface of a table truck 76 having a specially constructed supporting surface as will hereinafter be described.

Mounted above the conveyor mechanism 10 is a tank 80 (Fig. 4) for holding the desired tanning solution, a gage Abeing conveniently provided at one or both ends of the tank 80 to indicate the quantity of solution therein, the said gage comprising a transparent tube 81 connected with the tank and an indicator scale 83 which may be of a construction old and well known in the industry. From the tank 80 a pipe v'leads to a main,82 to which is' connected a number of flexible discharge tubes 84 and 86 (Fig. 1), the lower portions of which may be freely moved to discharge a treat-v ing liquid on the moving work, each discharge tube having a hand operated valve 85 so that the operator may control the amount of tanning liquid to be discharged therefrom upon any given piece of work.

Located adjacent to the table truck 74 at the entering end of the conveyor mechanism is a table truck 90 (Figs. l and 2) adapted to receive a stack of hides or skins 92 from any suitable source, to transfer them to a location adjacent to the -table truck 7fand to hold or support them inl such location that the hides or skins may be transferred one at a time to a work treating station on the stack ofY work supports 71. Subsequently the hide or skin is shifted to another station below the tube 84.

Located adjacent to the table truck 76 at the ldischarge end of the conveyor mechanism is a vat 94 (Fig. 2) also made in the form of a truck so that it may be readily transferable from one location to another.

For convenience in operating upon the. hides or skins there will be provided, as already stated, a plurality of portable backing members or work supports 71 shown in stack formation at 72 in Fig. 1. These backing members or work supports are in the form of mats or sheets without border pieces or thickened portions. Each mat or sheet is substantially the same thickness throughout and is ilexible, at least in its marginal portions, so that these portions are readily bendable upwardly above the plane of the body portion of the mat or sheet to form a container whereby the sheet may be readily transformed from a plane work supporting sheet to a container and vice versa. Y

When it is desired that the sheets shall serve as containers it is necessary only to place them upon face of which, as most clearly shown in Fig. 3

has marginal members 100 raised above the flat top 102 of the table truck. As shown in Fig. 3, a sheet or mat or backing member 71 placed on the table top 102 will conform more or less to the table top and to the marginal members 100 so that the marginal portions of the sheet or mat are bent upwardly, thus converting the sheet into a container whereby any liquid or liquids applied to the hide or skin on the sheet or mat will not escape vby draining therefrom. The work supports 71 which, as stated, are in the form of sheets or mats, should be light to be readily portable and should also be of material readily wetted by water, as will be hereinafter explained. EX- amples of substances which have these desired qualities are rubber or rubberized fabric, linoleum and Quaker felt. This last-mentioned substance, namely, VQuaker felt, is made of sheets of felt impregnated with as'phaltum and having sur- 4faces iinished with a iiexible paint or enamel.

As stated above, the mat or sheet should be of material which is readily wetted by water, that is, it` should be water-adherent so that a hide or skin slicked-out on one of its surfaces will adhere thereto to a considerable degree. Moreover, if the stack of mats' or sheets at 71 have their surfaces wet with water as they are stacked up on the table truck 74, they will readily be drawn up on to the belt conveyor 12, which also has a wateradherent surface, when a foot or more of one end of the mat or sheet has been engaged with the wet surface of the belt conveyor 12 passing around the roller 14. Because of this fact the workmen who stand on the opposite sides of the table truck 74 need not transfer each `work support 71 into full engagement with the belt conveyor 12, it being necessary only to shove each work support in turn up theslanting feedmg-in table until the forward end of the given work support 71 is engaged with the traveling belt conveyor l2 since in that case the light work support will be drawn onto the belt conveyor 12 and will'pass along the conveyor mechanism l0 in a position to have the work treated by other workmen Who stand on platforms 95 on opposite sides of the conveyor mechanism l0.

While certain advantages of the backing members or work supports 71. have been pointed out in the foregoing paragraph, the principal advantage of utilizing a light and readilyportable work support of the type herein disclosed resides in the fact that a hide or skin may be stretched out or slicked-out upon a surface of such a backing or work support and then subjected to treatment at dilerent stations and transported and stacked, if desired, while it remains in spreadv out or slickedout `condition on its work support. In other words, the worksupport becomes a backing or temporary stiffenin'g for the work and may be handled and treated as part of the work. While the hide or skin is in fully extended or slickedout condition on the backing or work support it is subjected to treatment by a tanning solution and then with its work support is removed from the table or bench where the work was done so that the operator or operators at said bench or table may continue operations on other pieces of work while the backing or Work support with its treated hide or skin is being carried off by a conveyor or other suitable means or stacked with other backings or work supports having similarly treated hides or skins thereon. All the time that the work support with its treated hide or skin is being moved by conveyor or otherwise or while it is in stacked relation to other similar work supports, the tanning material is acting on the hide or skin substance. provided, such as that shown in Fig. 4 of the drawings, the tanning material may have acted for a suflicient length of time when the hide or skin with its backing or work support reaches the other end of theconveyor, so that the hide or skin. now partially tanned or set in its extended condition, may be removed at once from its backing or support and subjected to other operations intended to complete the tanning of that particular hide or skin. Where a relatively short conveyor is used, like that shown in Fig. 1 of the drawings, the backing or work support with its treated hide or skin will lbe stacked with other similar backings or work supports having similarly treated hides or skins thereon. While the If a long conveyor be i skins are stacked the tanning material continues to act, restriction of evaporation by the backings serving to keep the tanning material in condition to permeate the skins and become uniformly distributed therein. In this Way, space is conserved since the portable work supports take up relatively little space as compared with benches or stationary work supports at which the operators must perform their work. Furthermore, time is saved in that the workers can remain at one station while the work is brought to them and removed again with little effort on their part. Again the tanning material continues to act while the backing or work support with its treated hide or skin is being moved to the desired location for stacking or for removal of the hide or skin from backing or its Work support.

In treating hides and skins with the apparatus disclosed in Figs. 1 to 3, inclusive, of the drawings, a stack of hides or skins 92 is placed upon the table truck 90 and the latter is located adjacent to the table truck '74 upon which a stack of backing members or work support '71 has been placed with both surfaces of each work support moistened with water. A hide or skin is transferred from the stack of the table 90 to the exposed surface of the top work support '71 of the stack 72. On this top work support a piece of Work if it be a heavy hide is spread out in substantially extended condition with all folds and wrinkles effaced. Hides are subjected to a putting-out operation before reaching the table 90. Each hide is then treated on its grain surface with a tanning solution obtained from the flexible tube 84 through proper manipulation of the valve 85 adjacent to the lower end of the tube. If the piece of work be a skin or light hide, it will be slicked out in fully extended condition while resting on the top Work support of the stack '72 and before the application of tanning material through tube 84. It will be understood that the workers at this station may make use of brushes or swabs to spread the tanning liquid substantially uniformly over the exposed grain surface of the hide or skin. However, it is preferred to have this done at another station, viz., at the feedingin table '70. The use of spraying devices for ap plying tanning material to the hides or skins is also contemplated. As soon as the application of tanning material has been accomplished, th work support with its treated hide or skin is shoved up the feeding-in table '70 until its forward end engages with the traveling belt conveyor 12, the upper surface of which is wet with water as above described. The work support '71 travels with the belt conveyor 12 and is soon in a position to be operated by workers, standing one on each side of the conveyor mechanism 10, who spread out the hide or skin after having reversed it by placing the grain surface down upon its backing or work support '71. Care is taken to do a thorough job of slicking-out on skins so that the latter may be extended to their full normal area upon the upper surface of the backing or work support 71. In performing this slicking-out operation a large proportion of the watery content of the skin, including some of the spent tanning solution, is removed therefrom and subsequently drains into the troughs at each side of the belt conveyor 12. After the slicking-out operation, which is performed while the work support '71 and the hide or skin thereon are traveling along with the belt conveyor v12, the latter discharges the work support 71 with its slicked-out hide or skin on to the discharge table '75 from which it is removed by a worker and placed upon the table truck '76. When placed upon this table truckv '76 the marginal portions of the backing or work support 71 bend upwardly for reasons given above, thus converting the plane sheet work support '71 into a container. As soon as the work support or backing 71 with its slicked-out hide or skin has been placed upon the table truck '76, strong or concentrated tanning solution, obtained from the tube 88 by proper manipulation of the'valve 85 is applied to the hide or skin, the tanning liquid being spread over the exposed flesh surface of the hide orskin in a uniform manner with the aid of a brush or a swab. Preferably the tanning solution is allowed to act upon the fully stretched Aout hide or skin for a time substantially just suicient to set the hide or skin in its fully extended condition. This means that the hide or skin is only partially tanned on the work support '71, but to such an extent that it will subsequently maintain this area while it is undergoing other operations intended to complete the tanning thereof. Conveniently each work support 71 with its slicked-out skin which arrives at the discharge table '75 will be placed upon the work support '71 which preceded it, and the hide or skin thereon treated as just described. In this way, the work supports 71 with their treated hides orskins are stacked up on the table truck '76 to a convenient height whereupon this tabletruck may be readily shoved to one side and an empty one substituted therefor. After the hides or skins have been left in the stack on the table truck 76 for a suflicient length of time, which may be as short as fiteeen minutes in the case of very thin skins but which may be for a period of hours and even over night, each hide or skin is removed in turn from its work support and placed'in a body of tanning solution such as that contained in the portable vat shown at 94 in Fig. 2a. This portable vat contains a quantity of the desired tanning solution, and as each hide or skin is placed therein both of its surfaces are thoroughly wetted with the tanning solution. Hides or skins thus placed individually in the solution in the vat 94 do not become closely packed together but are separated by a substantial lm of tanning solution. 'I'he tanning is readily finished in this vat with the hides or skins in fully extended condition. After the requisite length of time they are removed and finished in accordance with any of the old and well-known methods commonly employed in leather manufacturing establishments. While it is preferred with certain kinds of leather designed for certain purpose to nish the tanning in vats similar to that shown at 94, for certain other purposes the hides or skins, and particularly hides intended for sole leather. may be finished by drumming with a strong or concentrated solution of tanning material. Drumming hastens the penetration of the taning solution and, in the case of hides, loading of the hide with tanning material may be more readily accomplished than in a vat. d

In the modification shown in Figs. 4 and 5, the hides or skins are not treated upon individual work supports. Hence a table truck 110, located at the entering end of 'a belt conveyor v112, will have hides orskins 114 stacked thereon. Since the work of slicking-out and applying tanning solution to the hides and skins will be carried out while the hides or skins are traveling along with the upper run of the belt conveyor 112, the latter is made considerably longer than the corrirresponding belt conveyor 12 of Fig. 1. Otherwise L50 the belt conveyor mechanism of Fig. 4 may be similar in all respects to that shown in Fig. 1. At the discharge end of the belt conveyor 112 there is provided a vat truck 116 similar to that shown at 94 in Fig. 2 of the drawings.

In operating the apparatus disclosed in Figs. 4 and 5 for the treatment of hides and skins, a stack of hides or skins 114 is placed upon the table truck 110. In case heavy hides are being treated, they will be subjected to a putting-out operation in a machine provided for that purpose, before being placed upon the table truck 110. 'I'he top hide or skin with its grain surface facing upwardly is treated, while spread out to expose all portions of its grain surface, with tanning solution obtained from a exible tube 1118 through proper manipulation ofthe valve 120. This hide or skin is at once transferred by the worker to the belt conveyor'112. 'I'he worker or-workers at the conveyor mechanism at once reverse this hide or skin, placing the grain surface down upon the belt conveyor 112. Here, the piece of work, if it is a skin or light hide, is thoroughly slicked-out infully extended condition while being carried along on the conveyor, the slicking-out operation also removing a large proportion, approximately one-half, and, in some cases, the larger portion, of the watery contents of the hide or skin. A heavy hide is spread out in fully extended condition with -the grain surface down. Following this operation another worker will treat the exposed esh surface of the hide or skin with tanning solution from a flexible tube 122, a. brush or' swab being madeuse of to spread the tanning solution uniformly over the flesh surface of the slicked-ou't hide or skin. The belt conveyor 112 is'so long and moves at such a speed that several minutes will elapse from the application `of tanning solution through the tube 122 until such treated hide or skin reaches the discharge end of the belt conveyor 112. During this travel light hides an-d skins are partially tanned so that they may be removed by a worker without danger of losing their slicked-out area and immediately placed in a body of strong or concentrated tanning solution .in the vat 114, care being taken to see that the hide or skin is spread out in its fully extended condition in the vat. In case the hides or skins are of considerable thickness they may -be stacked upon a table similar to the table truck 76 of Figs. 1 and 3, where they will be allowed to remain until the tanning solutionhas struck into the hide or skin .substance suiliciently to give a set to the fibers thereof such that they will not subsequently shrink when introduced irto a vat or drum for the completion of the tanning operation. Here, again, the hides or skins may be drummed after they have been allowed to set for the required length of time. It is clear from the foregoing description, that the traveling belt conveyor 112 serves as a portable backing for one or for a number of skins at the same time, and that the improvedmethod of, treating hides and skins, as defined in the broader of the claims hereto appended, may be practiced vwith the aid of a. belt conveyor similar to that designated 112 in the accompanying drawings.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

f1. That improvement in methods of tanning hides and skins which comprises spreading out a hide or skin in fully extended condition on a portable backing whichl will maintain the hide or skin fully extended, treating the hide or skin with tanning material while it is maintained extended on said backing, and stacking the treated hide or skin, still spread out on said backing, in contactv hide or' skin, still spread out on its backing, in

contact above and below with other similarly treated hides and skins and their backings to continue the tanning of the hides or skins in the stack.

3. That improvement in methods of treating hides and skins which comprises slicking a hide or skin out in `fully extended condition upon a portable work support, applying a tanning solution to the exposed surface of the hide or skin on the work support, reversing the hide or skin on its work support and slicking it out again in fully extendedl condition on the portable work support and simultaneously therewith removing a large proportion of the water content of the hide or skin, and applying aV tanning solution to the slicked-out hide or skin to complete the tanning thereof.

4. That improvement in methods of treating hides and skins which comprises subjecting a hide or skin spread out in extended condition upon a portable work support to treatment by a tanning solution, transferring the portable work support with the treated hide or skin thereon to a station for further treatment, slicking the hide or skin out in fully extended condition on the portable work support, transferring the portable work support with the slicked-out hide or skin thereon to another station, applying a tanning solution to the slicked-out hide or skin, then removing the hide or skin from its portable work support, and placing the hide or skin in a body of strong or concentrated tanning solution to complete the tanning thereof.

5'. That improvement in methods of treating hides and skins which comprises spreading a hide or skin out in extended condition upon a portable work support, applying a tanning solution to the exposed surface of the hide or skin on the work support, transferring the portable work support with the treated hide or skin thereon to a station for further treatment, slicking the hide or skin out in fully extended condition on the portable work support and simultaneously therewith removing a large proportion of the water content of the hide or skin, transferring the portable work support with the slicked-out hide or skin-thereon to another station and applying a tanning solution to the slicked-out hide or skin, .stacking a number of the portable work supports with the treated hides or skins thereon, and permitting the tanning solution'to act for a time sufficient to set the fibers of each hide or skin before removal of the hides or skins from their work supports.

6. That improvement in methods of treating hides and skins which comprises spreading a hide or skin out in extended condition upon a portable Work support, applying a tanning solution to the exposed surface of the hide or skin on the work support, transferring the portable work support with the treated hide or skin thereon to a station for further treatment, slicking the hide or skin lou out in fully extended condition on the portable work support and simultaneously therewith removing a large proportion of the water content of the hide or skin, transferring the portable work support with the slicked-out hide or skin thereon to another station and applying a tanning solution to the slicked-out hide or skin, stacking a number of the portable work supports with the treated hides or skins thereon to permit the tanning solution to act for a time sufficient to set the bers of the hide or skin in each case before removal of the hides or skins from their work supports, re-

moving the hides or skins from their work supports after the hides or skins have had time to set each in its extended condition, and placing the hides and skins freshly removed from their work supports in a body of tanning liquid to complete the tanning thereof.

7. That improvement in methods of treating hides and skins which comprises spreading a hide or skin out in extended condition upon a portable work support, applying a tanning solution to the exposed surface of the hide or skin on the Work support, transferring the portable work support with the treated hide or skin thereon to a station for further treatment, slicking the hide or skin out in fully extended condition on the portable work support and simultaneously therewith removing a large proportion of the Water content of the hide or skin, transferring the portable work support with the slicked-out hide or skin thereon to another station and applying a. tanning solution t0 the slicked-out hide or skin, stacking a number of the portable work supports with the treated hides or skins thereon to permit the tanning solution to act for a time sufiicient to set the fibers of the hide or skin in each case before removal of the hides or skins from their work supports, removing the hides or skins from their work supports after the hides 0r skins have had time to set each in its extended condition, and placing each hide or skin individually in a body of tanning liquid in fully extended condition and in such manner that both surfaces of the hide or skin are thoroughly wetted by the tanning solution.

8. That improvement in methods of treating hides and `skins which comprises spreading a hide or skin out in extended condition upon a portable work support, applying a tanning solution to the exposed surface of the hide or skin on. the work support, transferring the portable work support with the treated hide or skin thereon to a station for further treatment, slicking the hide or skin out in fully extended Acondition on the portable work support and simultaneously therewith removing a large proportion of the water content of the hide or skin, transferring the portable work support with the slicked-out hide or skin thereon to. another station and applying a tanning solution to the slicked-out hide or skin, stacking a number of the portable work supports with the treated hides or skins thereon to permit the tanning solution to act for a time sufficient to set the bers of the hide or skin in each case before removal of the hides or skins from their work supports, removing the hides or skins from their work supports after the hides or skins have had time to set each in its extended condition, and drumming the hides or skins in a strong tanning solution to complete the tanning thereof.

9. That improvement in methods` of tanning hides or skins which comprises applying a tanning liquid to a series of hides or skins spread out each upon an individual portable backing,

stacking the portable backings with their treated hides or skins with each hide or skin between and in contact with two backings, and maintaining them stacked for at least a part of the time during which the tanning liquid continues to act.

10. That improvement in methods of tanning hides and skins which comprises slicking a hide or skin out in fully extended condition upon a portable Work support, applying tanning material to the slicked out hide or skin while at a given station, removing the portable work support and the treated hide or skin thereon from said station, permitting the treated hide or skin to remain on the portable work support until it is partially tanned in its spread-out condition, and then placing the hide or skin in a body of tanningv solution to complete the tanning operation.

11. That improvement in methods of treating hides and skins which comprises treating a hide or skin spread out in extended condition upon a portable work support With a tanning solution, stacking a number of the portable Work supports with the treated hides or skins thereon to permit the tanning solution to act for a time sufficient to set the fibers of each hide or skin before removal of the hides or skins from their Work supports, removing the hides or skins from their work supports after the hides or skins have had time to set each in its extended condition, and subjecting the hides or skins to treatment by a tanning solution to complete the tanning thereof.

12. That improvement in methods of treating hides and skins which comprises treating a hide or skin spread out in extended condition upon a portable work support With a tanning solution, stacking a number of the portable work supports with the treated hides and skins thereon to permit the tanning solution to act for a time sufficient to set the fibers of each hide or skin before removal of the hides or skins from their work supports, removing the hides or skins from their Work supports after the hides or skins have had time to set each in its extended condition, and placing each hide or skin individually in a body of tanning liquid in fully extended condition so that both surfaces of the hide or skin are thoroughly wetted by the tanning solution.

13. That improvement in methods of treating hides and skins which comprises treating a hide or skin spread out in extended condition upon a portable work support with a tanning solution, stacking a number of the portable work supports with the treated hides or skins thereon to permit the tanning solution to act for a time sufcient to set the fibers of each hide or skin before removal of the hides or skins from their work supports, removing the hides or skins from their Work supports after the hides or skins have had time to set each in its extended condition, and drumming the hides or skins in a strong or concentrated tanning solution to complete the tanning thereof.

14. That improvement in methods of treating hides and skins which comprises spreading out a hide or skin in fully extended condition upon a portable backing having flexible marginal portions, said spreading operation being performed while the portable backing is supported in at condition, applying a treating liquid to the exposed surface of the hide or skin, reversing the hide or skin upon its portable backing, bending up the marginal portions of the backing and, while said marginal portions are bent upwardly,

applying a larger quantity of treating liquid to the exposed surface of the hide or skin.

15. That improvement in methods of tanning hides and skins which comprises slicking out a hide or skin upon a portable backing having exible marginal portions, said slicking operation being performed while the'portable backing is supported in flat condition, applying a tanning liquid to the exposed surface of the hide or skin, reversing the hide or skin upon its portable backing, bending up the marginal portions of the backing and, While said marginal portions are bent upwardly, applying a larger quantity of tanning liquid tothe exposed surface of the hide or skin. l Y

16. That improvement in methods of tanning hides or skins which comprises spreading a hide or skin out in fully extended condition on a Ysheet of flexible material while' the latter is supported in flat condition, applying a tanning liquid to the exposed surface of the hide or skin while the marginal portions of the sheet oi material are maintained bent upwardly to prevent for the desired length of time the escape of any liquid, and stacking the sheet of material with its treated hide or skin with other similar sheets and skins.

17. That improvement in methods of tanning' hides or skins which comprises slicking a hide or skin out in`fully extended 'condition on a sheet of flexible material while the latter is supported in f lat condition, bending the marginal portions of the sheet of material upwardly to form a container adapted to prevent the escape of liquid, then applying a tanning liquid to the exposed surface of the hide or skin on said sheet of material, stacking the sheet of material with its treated hide or skin with other similar sheets and skins and with said marginal portions of the sheets in bent up condition to retain the tanning liquid, and permitting the tanning liquid to act on the stacked hides or skins for the desired length of time. Y

' MATTHEW M. MERRI'I'I. 

